They were two killings that have captivated and bewildered the people of their respective nations for decades.
The first involved a dashing, gambling-addicted aristocrat of a bloodline with links to the British royal family and the murder of his children's nanny.
The second concerned a tiny baby who was supposedly snatched by wild dogs from a campsite in the Australian Outback.
In the past few days, both the Lord Lucan and Azaria Chamberlain mysteries have hit the headlines once more, with new evidence surfacing in each case that offers hope that the truth, or something approaching the truth, will finally come out.
Take Lord Lucan's story: John Richard Bingham, the 7th Earl of Lucan, was in dire economic straights after losing a bitter divorce battle with his wife and some hefty losses in London's high-end gambling dens.
On the evening of November 7, 1974, someone used a lead pipe to smash in the skull of Sandra Rivett, the carer of his three young children, in the basement of his London house.
His former wife, Lady Lucan, was also attacked, but managed to escape and, covered in blood, stumbled to a nearby pub where she raised the alarm. Police issued an arrest warrant for Lucan, but three days later, a car he had borrowed from a friend was found abandoned at the port town of Newhaven.
An official inquest concluded that, full of remorse for the killing, Lucan probably threw himself off a boat into the murky waters of the English Channel. Conspiracy theorists, however, contend that, aided by his high-society contacts, Lucan absconded abroad to begin a new, secret life. Since then, he has been apparently "spotted" in various exotic locations, such as Kenya, South Africa, Australia and India.
These suspicions were substantiated last week in the BBC current affairs show Inside Out. It heard from a woman - allegedly the former secretary of Lucan's friend John Aspinall - who said she helped smuggle the fugitive to Africa following the murder. She also asserts that she booked holidays for Lucan's children, so he could view them "at a distance". The lady concerned did not show her face or give her real name, and Lady Lucan, in an article in The Telegraph, dismissed the claims as "nonsense". Nevertheless, at the end of the programme, a police spokesman admitted that any fresh evidence would be acted upon by officers.
Meanwhile, on the opposite side of the globe, this week a coroner's court has been re-examining the facts surrounding the infamous dingo homicide case.
On 17 August, 1980, in the shadow of Uluru (then known as Ayers Rock), nine-week old Azaria Chamberlain vanished from her parents' tent. Her mother, Lindy, claimed that she had witnessed a wild dingo snatching the infant from her cradle, although circumstantial evidence seemed to suggest otherwise.
Eventually Lindy faced trial, was convicted of murder and sentenced to life in jail, before the discovery of the baby's bloodied clothes in a dingo lair led to her being freed on appeal in 1988.
Despite this, Azaria's death certificate remains blank. Thus, Lindy Chamberlain-Creighton, who changed her name after remarrying, has pressured the establishment into launching a new coroner's probe into the death, which began last week in Darwin.
Whatever the outcome of these proceedings, will it really ease the propensity for some to doubt? The perceived ambivalence surrounding both cases means our fascination continues long after officials have recorded their verdicts. Even though we seek to resolve the unresolved in our minds and satisfy ourselves that an answer is within reach, many will continue to question. So sometimes, especially after the passage of time, as unsettling as it may be, there are mysteries that defy explanation and secrets that can't be fathomed. Did a dingo maul baby Azaria and did Lucan live out the rest of his days in some far-flung backwater? These new inquiries just act to obfuscate rather than illuminate the truth.